'I have Covid,' Jim Cramer says. He says he's been triple vaccinated and has a mild case

CNBC's Jim Cramer said Monday he has tested positive for Covid, and he's isolating at home.

"I have Covid. I came down with Covid on Thursday night," Cramer said on "Squawk on the Street." He added he's been triple vaccinated: two shots of Moderna and a Moderna booster.

"I know exactly how I got it," he said. "I was at an event where you had to have PCR [tests]."

"I got it that night from someone who was tested that day," he said. "The problem is it works so fast. You can't stop it.

Cramer said his wife is sicker than he is. "She had J&J and Moderna," he revealed, referring to the Johnson & Johnson Covid vaccine and a Moderna booster shot.

Moderna said before-the-bell Monday a third dose of its Covid vaccine appears to provide significant protection against omicron. Shares opened 9% higher but pared those gains shortly thereafter.

Without a booster, Moderna's vaccine has been been found to be far less effective against omicron. The company said it'll continue to develop an omicron-specific booster.

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